Boosting Performance Through Creative Surgery

Datsun 240Z with a BMW Inline-Six

Christopher was ready to move on from his 1987 BMW M6 to the next project. After realized there was little interest in the BMW M6, he would swap the freshly rebuilt inline-six and transmission into a 1972 Datsun 240Z. After three years of hard work this 240Z is a cut above the rest.

The first job was to find out if the BMW engine would even fit. After several test fits Christopher determined it would but not without modifying the oil pan and crossmember. He lowered the crossmember 1/2 inch and cut and lowered the center section of the crossmember 7/8 inch to achieve a total clearance of 1-3/8 inches. He brought the steering and suspension geometry back in alignment using offset tie rods and roll center spacers.

After the initial engine mockup the body was acid dipped. This removed all layers of paint and body filler exposing the bare metal and all the imperfections. Christopher repaired rust damage and stitched welded all the seams.

Christopher also used the opportunity to fabricate and install several braces to strengthen the body. He then sprayed the body in epoxy primer and sealed all seams.

With the body taken care of it was time to assemble all the pieces. Christopher lowered the built 3.5 L S38B35 inline-six into the bay with custom motor mounts. From the factory the engine produces 256 hp at 6,500 rpm and 242 lb-ft of torque at 4,300 rpm. However this particular one uses larger fuel injectors and a Megasquirt II ECU.

Christopher paired the engine with a Getrag five-speed manual transmission and R200 rear end from a Datsun 280Z. He upgraded the rear end with an OBX limited-slip differential and 3.90 gears.

The changes to the interior were subtle with a goal of looking factory. The most noticeable are Nissan 350Z seats and Speedhut gauges decorating the dash.

The braking system was completely rebuilt with new hard lines, SS braided flex hoses, and larger master cylinder from a 280Z. The front brakes use vented rotors with four-piston calipers from a Toyota 4×4 and the rear brakes are single-piston from a Maxima. Covering the brakes are a set of Rota Grid 16×8 bronze wheels wrapped in BFGoodrich G-Force Rival 225/50 tires.

Shortly after finishing the project the 240Z suffered engine damage. It turned out a poorly designed shim moved and blocked an oil passage. Fortunately Christopher shut the engine off quickly and mitigated the damage. After replacing the crank, bearings, and oil control rings, the engine is running great and Christopher is out enjoying his hard work. You can view more photos and details in the project’s build thread.